<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>Built in color maps</title><link rel="stylesheet" type="text/css" href="manual.css"><meta name="generator" content="DocBook XSL Stylesheets V1.76.0"><link rel="home" href="index.html" title="JpGraph Manual"><link rel="up" href="ch22.html" title="Chapter 22. Matrix graphs"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Built in color maps</th></tr><tr><td width="20%" align="left"> </td><th width="60%" align="center">Chapter 22. Matrix graphs</th><td width="20%" align="right"> </td></tr></table><hr></div><div class="sect1" title="Built in color maps"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="sec.built-in-colormaps"></a>Built in color maps</h2></div></div></div>
        
        <p>There are three types of built in color maps</p>
        <p>
            </p><div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem">
                    <p><span class="bold"><strong>Standard maps</strong></span></p>
                    <p>Includes rainbow spectrum and heat maps and combination of plain
                        red-green-blue maps</p>
                </li><li class="listitem">
                    <p><span class="bold"><strong>Normalized center</strong></span></p>
                    <p>These maps have a white:ish center. This is mostly useful to visualize the
                        spread from a center value</p>
                </li><li class="listitem">
                    <p><span class="bold"><strong>Continues</strong></span></p>
                    <p>The maps have one base color where the hue changes</p>
                </li></ol></div><p>
        </p>
        <p>In the color maps in the following section the black bars under some colors in the
            color map shows the discrete colors (the plateaus) that the color map is made up of. All
            colors in between two "barred" colors are linear interpolations.</p>
        <p>The script that was used to generate these color maps can be found under the example
            directory as "<code class="filename">colormaps.php</code>".</p>
        <div class="sect2" title="Standard maps"><div class="titlepage"><div><div><h3 class="title"><a name="id2594164"></a>Standard maps</h3></div></div></div>
            
            <p>To show heat gradient map 0 is the standard color map. To highlight the min and
                max values (to get a high contrast) map 3 is a good choice. Map two is a standard
                "rainbow" spectrum from red all up to violet.</p>
            <div class="figure"><a name="id2594175"></a><p class="title"><b>Figure 22.13. Standard color maps</b></p><div class="figure-contents">
                
                <div class="mediaobject"><img src="images/colormap_standard.png" alt="Standard color maps"></div>
            </div></div><br class="figure-break">
        </div>
        <div class="sect2" title="Normalized center"><div class="titlepage"><div><div><h3 class="title"><a name="id2594199"></a>Normalized center</h3></div></div></div>
            
            <p>These maps have a neutral (white) center and feathers out to the min/max value at
                each end.</p>
            <div class="figure"><a name="id2594207"></a><p class="title"><b>Figure 22.14. Centered color map</b></p><div class="figure-contents">
                
                <div class="mediaobject"><img src="images/colormap_center.png" alt="Centered color map"></div>
            </div></div><br class="figure-break">
        </div>
        <div class="sect2" title="Continues map"><div class="titlepage"><div><div><h3 class="title"><a name="id2594189"></a>Continues map</h3></div></div></div>
            
            <p>These maps changes continues from the min color to the max color.</p>
            <div class="figure"><a name="id2594238"></a><p class="title"><b>Figure 22.15. Continues color map</b></p><div class="figure-contents">
                
                <div class="mediaobject"><img src="images/colormap_continues.png" alt="Continues color map"></div>
            </div></div><br class="figure-break">
        </div>
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